Forces and their Interactions

• A scalar quantity is a quantity that only has a magnitude and is not direction dependent.
• A vector quantity is a quantity that has both a magnitude and an associated direction.
• A force is a push or pull acting on an object due to an interaction with another object.
• All forces can be split into two categories: contact forces (objects touching) and non-contact forces (objects separated).
• Examples of contact forces include friction, air resistance, and tension.
• Examples of non-contact forces include gravitational forces, electrostatic forces, and magnetic forces.
• Force is a vector quantity as it has both a magnitude and an associated direction.
• Examples of vector quantities include speed, acceleration, and velocity.
• Weight is the force that acts on an object due to gravity and the object’s mass.
• Velocity, Displacement, and Force are examples of vector quantities.
• The unit used for weight is the Newton (N).
• Temperature, Time, Mass, Speed, Distance, and Energy are examples of scalar quantities.
• Weight depends on the object’s mass and the gravitational field strength at the given position in the field.
• A calibrated spring-balance or newton-meter can be used to measure an object’s weight.
• The centre of mass is the single point where an object’s weight can be considered to act through.
• The resultant force is the name given to the single force that is equivalent to all the other forces acting on a given object.
• The unit used for gravitational field strength is N/kg.